Insecticidal product and process



Patented Dec. 7, 1937 UNITED STATES INSECTICIDAL PRODUCT AND PROCESSArthur A. Levine and Robert W. McAllister, Ni-

agara Falls, N. Y., assignors to E. I. du Pont de Nemours & Company,Wilmington, DeL,

poration of Delaware No Drawing. Application July 22, 1935,

Serial N0. 32,588

5 Claims.

This invention relates to a novel and a more satisfactory insecticide,and to a novel process of fumigating utilizing this insecticidalmaterial. More particularly the invention is concerned with the use ofcyclohexene oxide in the destruction of various insects which arefrequently encoun tered in fumigation.

Cyclohexene oxide is normally a liquid having a boiling point at normalatmospheric pressure of about 132 C. It has a relatively high vaporpressure and readily volatilizes if exposed to the atmosphere. However,it is not so volatile as to develop a considerable gas pressure iftransported as a liquid in a closed container of comparatively smallstrength such as a carboy or bottle. Our novel insecticide, cyclohexeneoxide, has the following structural formula:-

and is especially valuable for the destruction of various objectionableinsects such'as the common clothes moth larvae, the granary weevil, theconfused flour beetle, aphis or plant lice, cock roaches, and bedbugs.

Ethylene oxide has previously been used as an insecticide but since thiscompound is a liquid having a relatively low boiling point, about 14 C.at normal atmospheric pressure, difficulties have been met with inhandling and transporting it. In commercial practice it is nowtransported in pressure-resistant cylinders and for this reason it ispractically impossible to use for household fumigation as some othermaterials.

Naphtha.lene and paradichlorbenzene have also been used in householdfumigation, particularly for the destruction of the larvae of the commonclothes moth. While efiective, these compounds impart a very pungent anddisagreeable odor to clothes stored in the closets in which thesemothicides are employed, which odor does not leave the garments untilthey have been thoroughly aerated. Moreover, the efiective concentrationof Vapors of paradichlorbcnzene and naphthalene necessary to destroyclothes moth larvae when these mothicides' are used in anabsolutelytight container or closet is relatively high. Government authoritiesrecommend the use of vapor concentrations of paradichlorbenzene andnaphthalene as high as 10 pounds per 1000 cubic feet fumigated forsatisfactory destruction of the larvae of the clothes moth.

In utilizing cyclohexene oxide as an insecticide or mothicide, theliquid maybe sprayed into a space to be fumigated or on the clotheswhich are to be mothproofed. Similarly, an enclosed space such as acloset, trunk, or storage chest, 5 may be filled with vapors ofcyclohexene oxide by spraying some of the liquid into these spaces.Another satisfactory way of utilizing cyclohexene oxide directly in theliquid state, is to leave a quantity of the oxide exposed to theatmosphere in an enclosed space to be fumigated in a relatively shallowdish. As a result of the evaporation of the cyclohexene oxide due to itsrelatively high vapor pressure, the space will become filled with vaporsof the compound. This latter method may be used for fumigating closets,other enclosed spaces for the storage of clothes, granary storagespaces, flour bins, greenhouses, or machines which handle food productsand are periodically fumigated to destroy insect life.

cyclohexene oxide is especially suitable for fumigating machines whichare periodically fumigated since insect destruction may be ef- .fectedwithout shutting down the operation of the plant. This is becausecyclohexene oxide,. as distinguished from other fumigants such ashydrocyanic acid orsulfur dioxide, is not highly toxic or noxious toworkers operating the other processes carried on in the plant. It hasalso been found particularly valuable as a, mothicide since the odorimparted to the clothes which is not necessarily objectionable ordisagreeable in itself and, as contrasted with some other mothi cidematerials, very rapidly leaves the garments upon exposure to the openair. This rapidly disappearing property of odors resulting fromcyclohexene oxide vapor is especially desirable since garments stored ina closet fumigated with this I material need be aerated for but a veryfew minutes and will then be free from noticeable odor.

Since cyclohexene oxide is a liquid it may be more desirable in somecircumstances to prepare solid mixtures containing an amount ofcyclohexene oxide which will yield vapors of the insecticide in thedesired amount to the air present in the space to be fumigated. One verysatisfactory way of preparing solid fumigant mixtures containingcyclohexene oxide is to admit a quantity of the liquid cyclohexene oxidewith a molten wax such as parafiln, spermaceti wax, carnauba wax orbeeswax. In this way a relatively hard solid product can be obtained. Arelatively inex pensive paraifin wax is of course the preferred wax withwhich cyclohexen'e oxide is to be admixed, because of its low cost andavailability. 55

of about two days.

We have found that a mixture containing 65% of paraffin and 35%cyclohexene oxide, these percentages being by weight, forms a verysatisfactory solid product. If a larger quantity of cyclohexene oxide isused with paramn, such as a 50% concentration, the resulting wax islikely to be soft and viscous rather than a hard solid. We thereforeprefer to employ a mixture of 65% parafiin and 35% cyclohexene oxide inour novel insecticide which mixture will provide a relatively highconcentration of vapor when using but a relatively small amount of thesolvent. When using other and relatively harder Waxes such as carnaubawax or spermaceti wax a larger amount of cyclohexene oxide can beadmixed with the molten wax and still obtain a solid and relatively hardproduct. If desired, small amounts of porous substances such askieselguhr, diatomaceous earth, or bentonite may be mixed with the waxcyclohexene oxide mixture. When using these solid products for thedestruction of insects the solid may be made up into the form of smallballs or flakes similar to the naphthalene and para dichlorbenzenemothicides now sold for household use. Small amounts of the solid may beplaced in the pockets or folds of the garment or exposed to theatmosphere in food product machines or other enclosed places whereininsect life is to be exterminated. If the very rapid evolution offumigant vapors from cyclohexene oxide is desired, a small amount of thesolid mixture of wax and cyclohexene oxide may be rapidly volatilized byplacing it upon a heated plate; or, if desired, the liquid may berapidly volatilized from any heated surface. For example, a hot iron ora brick which has previously been heated may be used as the vaporizationsurface for volatilizing cyclohexene oxide or for obtaining a rapidevolution of the vapors of the novel fumigant from the wax-cyclohexeneoxide solid. By the rapid evolution of vapors very rapid de struction ofinsects in the enclosed space fumigated may be obtained. Under somecircumstances equally rapid evolution can be obtained by spraying oratomizing cyclohexene oxide as a liquid into the enclosed space.

In the various experiments undertaken, th toxicity of cyclohexene oxidevapors for various insects such aslarvae of the common clothes moth, thegranary weevil, the confused flour beetle, aphis or plant lice,cockroaches and bedbugs, has been very carefully determined. Theseinsects are those most frequently encountered in household, greenhouseand industrial fumigations. For killing the clothes moth larvae, theconcentration of vapors of cyclohexene oxide in the enclosed spacefumigated should range from 0.5 to 2.0 pounds per one thousand cubicfeet of space. When the lower concentration is used substantially allthe larvae are killed in a period When using concentrations as high as1.5 to 2.0 pounds of cyclohexene oxide vapor per thousand cubic feet ofcloset space, the larvae are entirely destroyed in periods of time asshort as six hours or less.

When combating the granary weevil, which is one of the most difiicultinsects to exterminate among those which are encountered frequently inindustrial fumigation, amounts of the order of 3.0 to 4.0.pounds ofcyclohexene oxide vapor per thousand cubic feet of space fumigated, aredesirable. Aphis or plant lice, may be killed with amounts as low as 0.5pound of cyclohexene oxide per thousand cubic feet of space, while theconfused fiour beetle will ordinarily require about 2.0 pounds perthousand cubic feet for rapid and efiicient destruction. For killingcockroaches and bedbugs amounts of the order of 2.0 pounds per thousandcubic feet are also satisfactory. It may be mentioned that whencyclohexene oxide is used solely as a repellant, i. e., merely forrepelling rather than destroying any of the other insects mentioned, theamount of cyclohexene oxide present as vapor in the enclosed spacefumigated may be somewhat less than 0.5 pound per one thousand cubicfeet.

Cyclohexene oxide is especially valuable for fumigating flour mills,cereal mills and macaroni factories and the rolls, conveyors, elevatorlegs, and sifters of these factories. Many types of insects areencountered in such industrial insect destruction problems. Many factorymachines such as shredders, conveyors or molding machines are fumigatedregularly at frequent intervals, often while workmen are present in theplant operating other machines. Cyclohexene oxide, by reason of its notunpleasant odor and relatively low order of toxicity, as Well as itsrelatively high vapor pressure, is especially valuable for such use. Itlends itself readily to fumigating, either by the drip method or by theenclosed space method, 1. e., either by dripping the fumigant orinsecticide periodically into the open and uncovered machine or byenclosing the machine so that it is separated from the other space inthe workroom and then fumigating the machine by volatilizing cyclohexeneoxide in the space thus enclosed. For these purposes either liquidcyclohexene oxide or the solid mixtures described may be utilized.

The various details and amounts herein specified are to be considered asillustrative and not restrictive, the scope of our invention beingdetermined by the appended claims. Various changes might be made in thespecific proportions or amounts of cyclohexene oxide or cyclohexeneoxidewax mixtures used without departing from the scope of theinvention.

We claim:

1. An insecticide comprisingcyclohexene oxide.

2.- A mothicide and moth repellent comprising cyclohexene oxide.

3. An insecticide comprising a solid mixture of cyclohexene oxide and awax.

4. An insecticide comprising a solid mixture comprising approximately35% of cyclohexene oxide and 65% of paraflin.

5. An insecticide comprising a solid mixture of cyclohexene oxide and awax selected from the group which consists of paraffin wax, carnaubawax, and spermaceti wax.

ARTHURA. LEVINE. ROBERT W. MCALLISTER.

